Telegraph apparatus



July 25, 1939. SALMON 2,167,527

TELEGI-iAPH APPARATUS Filed March 5, 1956 Sheets-Sheet 1 Fig. I

ATTORNEY July 25, 1939. R. D. SALMON ,167,5 7

, TELEGRAPH APPARATUS 2 Sheets-Sheet 2 Filed March 5, 1936 e. 0. sAz/w/v Patented July 25, 1939 TELEGRAPH APPARATUS Reginald Dennis Salmon, Croydon, England, assignor to Creed and Company Limited, Croydon, England Application March 5, 1936, Serial No. 67,257 In Great Britain July 27, 1935 Fig. 1 is a vertical sectional view of a device according to the invention;

Fig. 2 is a side elevation;

Fig. 3 shows the Wards representing a character on the character bearing drum;

Fig. 4 is an enlarged view of one of the levers 9 Claims.

This invention relates to teleprinter apparatus and more particularly to devices used in connection therewith which in response to a particular signal automatically transmit a signal or series of signals to identify the particular transmitting station, commonly known as answer back devices. 7

The object of the invention is to provide an answer back device that can transmit a large number of characters and which will be compact, and simple in construction and cheap to manufacture.

In United States Patent No. 1,879,524, to Reginald D. Salmon and Frank R. Thomas, issued September 27, 1932, is described such a device in which on the receipt of a particular signal a shaft was released for one revolution and a cam thereon actuated a pawl to step round a drum having thereon representations of the characters to be transmitted. This drum acted upon the combination bars normally acted 'on by the keys of the keyboard. The cam also caused the de pression of the universal bar for each step of the drum. The shaft upon which this cam was mounted was separate and distinct from the normal transmitter cam shaft.

According to one feature of the present invention receipt of the signal requiring identification of the station automatically and directly releases the normal transmitting cam shaft, a cam on which in turn effects the step by step rotation until a complete identification message has been sent.

By this arrangement a cam shaft and friction clutch as well as the gearing for driving the cam shaft at a comparatively low speed are elimi nated.

According to another feature of the invention the wards representing signal elements are so arranged on the character bearing drum that there is a ward for each element of each character, the nature of the element being determined by the position of the ward.

By this means the character drum is adapted to a transmitter of the kind in which each combination bar is moved in one or the other direction according to the nature of the element. The position of the ward may determine which of two levers is actuated, the levers determining the respective directions of movement of the combination bars.

The invention will be better understood from the following description of one embodiment thereof taken in conjunction with the accompanying drawings in which I0, 12in Fig. 1, whilst Fig. 5 is a plan view of the levers I 3, E2 in Fig. 1. Referring to the drawings: The drum i5 carries a number of wards, for eXampletwentyround its circumference. Each one of these wards is made as shown in Fig. 3, where it will be seen that they are out with teeth to form combinations.

The teeth are adapted to engage with the nose of bellcranks IE] and I2, the other ends of which engage with combination bars H.

The

teeth on the wards are cut in such a manner that there is only one tooth for each pair of levers ii! and I2.

Consequently, if one lever is engaged with a tooth the other lever will be free, and the combination bar will be positively moved from one direction to the other, according to the lever which has been engaged. The ends of levers it and I2 are shaped so as to give a suitable motion to the combination bar as the drum Hi rotates. H

An enlarged view of the end of one lever is shown in Fig. 4.

For the purpose of, rotating the drum ratchet wheel 16 is mounted thereon, and engaged by a pawl I3 and a retaining pawl not shown.

Pawl I3 is carried by a three-armed bellcrank lever 5, one arm of which is adapted to engage with a cam 4 on the transmitting spindle H, and the other arm of which is adapted to engage with the latch end of lever l. to be retracted by spring I8, and to be positively The pawl is adapted fed forward by the cam 4. Lever I is also adapted to engage with an extension on the detent 59 which normally acts to arrest the rotation of the transmitting spindle I! by engaging with stop arm 3.

levers 2| nism.

Drum

Combination bars II also engage with which control the transmitting mechal5 also carries a cam 2| engaging with known manner.

Detent I9 is adapted to be released whenever the keybar is depressed, and transmitting spindle ll is adapted to make one revolution, and then come to rest, in well-known manner.

When it is desired to operate the answer back device; lever I is depressed under the control of a signal, either mechanically or by means of an electro-magnet. The depression of lever I, acts to release lever 5, so permitting it to retract pawl I3 under the action of spring I8, and to fall against the cam 4 of transmitting shaft [1. Lever I also acts on extension 2 of detent I9 to release the transmitting shaft I! so that it can rotate. The rotation of the transmitting shaft ll operates lever 5, thus feeding forward the answer back drum I5 through a distance equal to one tooth of the ratchet wheel, and consequently through an angular distance equal to the distance between two wards on the drum. As the transmitting spindle I'I continues its rotation the lever 5 is retracted again by means of spring l8, so that the pawl l3 will engage with a fresh tooth on the ratchet wheel I6. The first feeding movement of lever 5 in rotating drum I5v also moves cam 2| so as to permit lever B to rotate in an anti-clockwise direction under the action of its spring, and consequently to move the extension [4 towards the left, so as to hold the latch end of lever I out of engagement with the end of the arm on lever 5, and also to hold the pawl I9 out of the path of the detent 3 on the transmitting spindle I1. Thus, instead of the transmitting spindle being arrested at the end of one revolution it will continue to rotate, thus feeding forward the answer back drum [5. This will continue for every revolution of transmitting spindle l1, and the answer back spindle will be fed through a distance of one ratchet tooth for every revolution of the transmitting spindle, until the answer back drum I5 has completed one revolution, when the nose on cam 2| will engage with lever 6, thus withdrawing extension I4, and leaving lever I free to re-engage with lever 5 the next time it it operated by the cam on transmitting spindle Il, and also leaving the pawl I9 free to engage with the detent 3 when the transmitting spindle I'I completes its last revolution.

It is clear that more than one cam such as 2| may be provided. If the message to be sent comprises less than half or less than a quarter.

of the total capacity of drum I5, the message may be duplicated or quadruplicated and a cam having two or four humps is provided to stop the operation after one half or one quarter of a revolution respectively of drum.

For every feeding stroke of pawl I3 the drum I5 was rotated, and consequently the wards carried by the drum acting on the levers I and I2 set the combination bars I I to any desired combination,

The timing of cam 4 on transmitting spindle I I is such that the feeding stroke of pawl I3 occurs during the transmission of the starting and stopping signals, and the drum I is stationary during the transmission of the five combination signals.

What is claimed is:

1. In combination, a keyboard transmitter and a receiving printer, a cam shaft in said transmitter for controlling the sequential operation thereof on a key of the said keyboard being depressed, detent means for holding the said cam shaft stationary, means operable on the depression of any key for releasing said detent, a selector bar in said printer adapted to be actuated on receipt of a particular signal, mechanical means operable on the actuation of said selector bar in said printer to release said detent, and a physical connection between the actuated selector bar and said cam shaft for controlling means to transmit a signal or group of signals characteristic of said transmitter.

2. In combination a keyboard transmitter and a receiving printer, a series of notched combination bars, means to set said bars in varying combinations in accordance with the respective keys of the said keyboard, a transmitting contact tongue in said transmitter, a first cam means in said transmitter for actuating said contact tongue selectively in accordance with the setting of said combination bars, a second cam means in said transmitter for actuating said combination bars independently of said keyboard, a selector bar in said printer adapted to be actuated on receipt of a particular signal, means responsive to the actuation of said selector bar for initiating the operation of the first mentioned cam means and for placing the rotation of said second mentioned cam means under control of said first mentioned cam means.

3. In combination, a keyboard transmitter and a receiving printer a cam shaft in said transmitter for controlling the sequential operation thereof, means for setting said cam shaft into rotation for a predetermined degree of revolution only on depression of a key of the said keyboard, means in said receiving printer adapted to be operated on receipt of a predetermined signal to set said cam shaft into revolution independently of said keyboard, a physical connection between said last mentioned means and said cam shaft for controlling means to transmit a signal or group of signals characteristic of said transmitter, to keep said cam shaft in rotation until the said signal or group of signals has been completely transmitted and thereafter to arrest said cam shaft.

4. A keyboard transmitter having a series of combination bars, means to move said bars in varying combinations longitudinally in both directions in accordance with the respective keys of the said keyboard, means for controlling signalling contacts in accordance with the setting of said combination bars, a drum arranged to cooperate with said combination bars, and bearing wards representing the characters of a message to be transmitted, comprising a ward for each element of each code combination of each signal character carried by said drum, said wards being positioned on said drum to act upon said combi nation bars independently of said keyboard to move the respective bars in the two directions according to the respective elements of the characters.

5. In combination, a keyboard transmitter and a receiving printer, a first cam means in said transmitter for controlling the sequential operation thereof on a key of said keyboard being depressed, a second cam means for effecting the transmission of a group of signals characteristic of said transmitter, means in said receiving printer adapted to be operated on receipt of a predetermined signal to release said first cam means for rotation and to place the rotation of said second cam means under control of said first cam means, and a physical connection between the last mentioned means and said second cam shaft for controlling the transmission of said signals.

6. In combination, a keyboard transmitter and a receiving printer a first rotatable cam means in said transmitter for controlling the sequential operation thereof, means operable on depression of any key of the said keyboard for releasing said first cam means for a predetermined degree of rotation, and for causing the transmis sion of the code combination characteristic of said key, a second cam means, a ratchet wheel for efiecting step by step rotation thereof, cams on said second cam means for causing the transmission of a group of signals characteristic of said transmitter, a pawl, a cam on said first cam means for actuating said pawl to step said ratchet wheel, a selector bar in said printer adapted to be actuated on receipt of a particular signal, means responsive to the actuation of said selector bar for releasing independently of said keyboard said first cam means for rotation and for positioning said pawl to be actuated by said cam, a physical connection between said selector bar and said second cam means and for controlling the transmission of said signals, means associated with said second cam means for arresting said first cam means on completion of transmission of said group of signals.

'7. In combination a keyboard transmitter and a receiving printer, a series of combination bars adapted to be set by the depression of any key of the said keyboard in a combination depending on the particular key depressed, a first rotatable cam means for determining the successive transmission of elements of a signal according to the setting of said combination bars, detent means for holding said first cam means stationary, means operable on depression of any key for withdrawing said detent to allow said first cam means to rotate and for restoring said detent to arrest the rotation of said first cam means after a predetermined degree of rotation, a second rotatable cam means for setting said combination bars during its rotation into successive combinations representing successive signals of a group of signals characteristic of said transmitter, means in said printer operative in response to the receipt of a predetermined signal for withdrawing said detent and placing the rotation of said second cam means under control of said first cam means, and a cam on said second cam means for restoring said detent to operative position.

8. A keyboard transmitter comprising a series of combination bars adapted to be moved longitudinally in either direction by the depression of any key of the said keyboard in a combination depending on the particular key depressed, means for controlling contacts in accordance with the setting of said combination bars, selector levers for each combination bar arranged to move the said bar longitudinally in the respective directions independently of said keyboard, a drum bearing wards arranged to act on said selector levers to set said combination bars in accordance with a predetermined message to be transmitted, and means for rotating said drum. comprising a transmitting contact tongue, sig- 9. .In combination a telegraph transmitter nal responsive apparatus, a rotatable cam shaft in said transmitter for determining the successive actuation of the said contact tongue in accordance with the elements of a signal to be REGINALD DENNIS SALMON. 

